ISO/IEC 23360-2-2:2021

Overview

ISO/IEC 23360-2-2:2021 - Linux Standard Base (LSB) - Part 2-2: Core specification for X86-32 architecture defines the architecture-specific portion of the LSB Core for 32-bit x86 systems. It supplements the LSB Core - Generic document to provide a complete binary interface (ABI) and minimal runtime environment for compiled applications and installation scripts on x86-32 platforms. This edition (first edition 2021) replaces the earlier ISO/IEC 23360-2:2006 and is maintained under the LSB program.

Key topics and technical requirements

• Binary interface (ABI) focus: The specification is primarily an Application Binary Interface definition that lists mandatory ABIs for conforming implementations; it complements source-level APIs contained in other referenced standards.
• Architecture-specific details: Defines x86-32 machine interface elements such as calling conventions, C stack frame, process initialization and low-level system information required for portable binaries.
• Executable and Linking Format (ELF): Covers object format requirements, ELF header and special sections, symbol tables, relocations, program header, program loading and dynamic linking behavior for x86-32.
• Base and utility libraries: Enumerates required libraries and interfaces (examples include libc, libm, libpthread, libgcc_s, libdl, libcrypt, libz, ncurses), data and interface definitions that implementations must provide.
• Package and installation considerations: Specifies minimal environment expectations for installation scripts, package architecture considerations and dependency semantics for distributing high-volume applications.
• Conformance and versioning: Explains LSB conformance rules for implementations and applications, the LSB versioning scheme (major/minor/editorial) and encourages symbol versioning to maintain backward compatibility.
• Mandatory vs optional: Interfaces described are mandatory except where explicitly noted otherwise.

Practical applications and target users

• Software vendors and independent software vendors (ISVs) seeking binary portability across Linux distributions on x86-32.
• Distribution maintainers and OS integrators implementing LSB-conforming runtimes.
• Toolchain and compiler developers ensuring produced binaries match the x86-32 ABI expectations.
• Packagers and release engineers who prepare installation scripts and packages for broad deployment.
• QA, certification bodies and developers who need a deterministic runtime and library set for high-volume or commercial applications.

Related standards

• LSB Core - Generic (the common part referenced by this architecture-specific part).
• Other parts of the ISO/IEC 23360 series (LSB modules and architecture parts) that together define the complete LSB specification.

Keywords: ISO/IEC 23360-2-2:2021, Linux Standard Base, LSB, X86-32, ABI, API, ELF, libc, dynamic linking, package format, binary portability.